Today most windows are provided in the form of a unit which includes one or more glass panes mounted in a frame. The glass panes typically comprise sealed double-or triple-glazed panels. The frame is typically made of vinyl or another plastic material which does not conduct heat well although some aluminum-framed window units are still sold. The frame of each window unit typically includes a broad flange which projects in a lateral direction and extends around the periphery of the window unit. Other types of prefabricated construction units such as doors, vents and sunlights may have similar flanges.
A typical wood frame building has a frame of wooden members which includes apertures for prefabricated construction units such as windows, doors, vents, sunlights and the like. An appropriately-sized construction unit is received in each of the apertures with the flange overlapping with and abutting the outside of the building frame. The construction units are typically secured in place by placing a few screws or nails through the flange into the building frame on each side of the construction units.
One disadvantage of the way that construction units are currently installed is that a person must be outside of the building to install the construction units. This is especially problematic for window units, since window apertures may be located well above ground level. Windows in such locations are often installed by a person standing on a ladder. This can be dangerous, especially if the weather is windy or during winter conditions.
Another disadvantage of the way that construction units are currently installed is that many buildings have a waterproofing membrane applied to their exterior. Puncturing the membrane with screws or nails reduces the effectiveness of the membrane.
There is a need for more efficient ways to install construction units.